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ramapcsx2 / gbs-control

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Custom preset from known SYNC oscillogramme / timings #226

Open nightgryphon opened 3 years ago

nightgryphon commented 3 years ago

How can i build and upload custom preset in case i can record the exact sync signal with logic analizer and measure any part of this signal? I have problems with GBS Control on some retro PC like "УКНЦ МС 0511" and some others. There is no or unstable picture. But i see the sync is valid and both TV and old tube monitor can recognize it. Can i manually create the required preset when GBS auto detect fails?

Here is the example SYNC graph captured with logic analyzer at the output of video processor before mixing image

zajc3w commented 3 years ago

I have similar problem, I have CNC screen to replace, 18.3khz h-sync, 50hz v-sync. I get right half of the screen cut off. TV5275 is poorly documented and changing output res to something useful for me(1024x768) took a day of hex editing. If there is profile generator it's not known to duckduckgo nor google. all i got is register description PDF and programming manual, which isn't the greatest help. now I'm stuck on input shifting. I have some black empty on the left and right edge cut off. No matter how I try to move it in web GUI I get green garbage on the right. Signal works perfect on borrowed CRT and looks ok on oscilloscope - video signal is not overlapping h-sync polarities are correct.

ramapcsx2 commented 3 years ago

There is a serial command parser in the code. You send it characters and it does them. You can use this to quickly set the main parameters of a preset, such as the number of lines, and it'll figure out what to configure to get them. Example: "wvt 1066" means "write vertical total 1066", which would produce enough lines for an x1024 preset. Here is the parser, sadly undocumented (I wrote it for myself :p) https://github.com/ramapcsx2/gbs-control/blob/master/gbs-control.ino#L8230

ramapcsx2 commented 3 years ago

You also need to google how to read modelines, then use a modeline list (https://www.mythtv.org/wiki/Modeline_Database#VESA_ModePool) to find some main parameters of presets. Your x768 preset would use 806 total lines, for example (wvt 806)